To impersonate someone means to pretend to be them by copying their voice, mannerisms, appearance, or behavior. When a comedian impersonates a famous person on a television show, they might mimic how that person talks, walks, and gestures to make the audience laugh. An actor might impersonate a historical figure in a movie, studying old recordings to capture exactly how they spoke.

Impersonation can be entertaining and harmless, like when friends playfully impersonate their teacher's way of saying “Now, class...” But it can also be serious and illegal. Someone who impersonates a police officer or doctor is committing a crime because they're deceiving people who trust that uniform or title. Online, criminals sometimes impersonate banks or companies to trick people into sharing passwords or personal information.

The key difference from simply acting or pretending is that impersonation involves taking on a specific person's identity, not just playing a general role. When you dress up as a ghost for Halloween, you're not impersonating anyone. But if you dress as Abraham Lincoln and practice his speaking style for a school presentation, you're impersonating him. Whether impersonation is creative fun or serious deception depends on the intent and context.